Ophthalmic treatment device and method for driving same

ABSTRACT

The present invention relates to an ophthalmic treatment device and a method for operating the same. The present invention provides an ophthalmic treatment device and a method for operating the same, the ophthalmic treatment device comprising: a treatment beam generation unit for generating a treatment beam; a beam delivery unit for forming a path along which the treatment beam generated from the treatment generation unit is delivered to a treatment area positioned on the fundus; a monitoring unit for emitting a detecting beam along the path of delivery of the treatment beam and sensing treatment area state information on the basis of information regarding a change in speckle of the detecting beam, which is scattered and reflected from the treatment area; and a control unit for controlling the driving of the treatment beam generation unit on the basis of the treatment area state information sensed by the monitoring unit.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a U.S. National Stage of International PatentApplication No. PCT/KR2015/007994 filed Jul. 30, 2015, which claimspriority to and the benefit of Korean Patent Application No.10-2014-0097481 filed in the Korean Intellectual Property Office on Jul.30, 2014, the entire contents of which are incorporated herein byreference.

TECHNICAL FIELD

The present invention relates to a laser treatment device and a methodof driving the same, and more particularly, to an ophthalmic treatmentdevice and a method of driving the same that detect a state of atreatment area in which a treatment is performed and that controltreatment contents.

BACKGROUND ART

Nowadays, technology is widely used that performs a treatment with amethod of changing a tissue state by light energy absorbed to a humanbody tissue by radiating light to a human body. Particularly, atreatment device using laser is widely used for various lesions such asskin disease, eye disease, nerve disease, joint disease, and gynecologydisease.

Particularly, as an ophthalmic treatment device using laser, a pluralityof devices for treating an anterior segment lesion of eye such askeratoplasty, glaucoma, or cataract operation have been developed, andnowadays, a device for treating various lesions of a fundus area as wellas macular degeneration has been developed. Such an operation device isdisclosed in Korean Patent Laid-Open Publication No. 10-2014-0009846.

In this way, when performing a treatment with an ophthalmic treatmentdevice using light, it is necessary to continuously monitor a state of aposition in which the treatment is performed. However, as in aconventional case, when using ultrasonic waves or an optical sensor suchas a Charged Coupled Device (CCD) or a Complementary Metal-OxideSemiconductor (CMOS), an internal state of a treatment area cannot bemonitored or there is a limitation in detecting a micro change of atissue.

DISCLOSURE Technical Problem

The present invention provides an ophthalmic treatment device and amethod of driving the same that can monitor in real time a state changeof the inside of a tissue of a treatment area while performing atreatment and that can perform a treatment based on the monitored statechange.

Technical Solution

In accordance with an aspect of the present invention, an ophthalmictreatment device includes: a treatment beam generation unit thatgenerates a treatment beam; a beam delivery unit that forms a path thatadvances a treatment beam generated by the treatment beam generationunit to a treatment area positioned at a fundus; a monitoring unit thatradiates a detecting beam along an advancing path of the treatment beamand that detects speckle pattern information of the detecting beamscattered or reflected from the treatment area to detect stateinformation about the treatment area; and a control unit that controlsdriving of the treatment beam generation unit based on state informationabout the treatment area detected in the monitoring unit.

Here, the monitoring unit may detect state information about thetreatment area based on interference information of the detecting beamscattered or reflected from the treatment area.

Specifically, while the treatment beam is radiated at a predeterminedposition, the monitoring unit radiates the detecting beam multiple timesto the predetermined position to detect state information about thepredetermined position. The monitoring unit may compare stateinformation detected by each detecting beam with state informationdetected by the previously radiated detecting beam to determine a statechange of the treatment area.

Here, the monitoring unit may selectively extract informationcorresponding to an interest depth region among state informationdetected by the each detecting beam and compare information about theextracted interest depth region with information about an interest depthregion detected by a previously radiated detecting beam to determinewhether a state of the treatment area is changed.

In this case, the interest depth region may be an area including an RPEcell layer of the treatment area. Alternatively, a depth correspondingto the interest depth region may be directly set by a user through aninterface.

Here, the monitoring unit may detect a temperature change of a treatmentarea occurring when the treatment beam is absorbed in the treatmentarea. A characteristic of the light path, along which the detecting beamadvances, changes, when a refractive index or a volume of a tissuepositioned at the treatment area changes with temperature increase ofthe treatment area, and the monitoring unit may detect a speckle patternchange according to the light path characteristic change of thedetecting beam to detect a temperature change of the treatment area.

For example, the monitoring unit may determine that a temperature of theRPE cell continuously increases, if a change amount of a speckle patternof the reflected detecting beam is in a predetermined range anddetermine that the RPE cell is necrotized, if a change amount of aspeckle pattern of the reflected detecting beam exceeds a predeterminedrange.

Specifically, the monitoring unit may include: a light source thatradiates the detecting beam to a treatment area; a detection unit thatdetects a speckle pattern of the detecting beam reflected from thetreatment area; and a processor that extracts information about aportion adjacent to an RPE cell layer in a speckle pattern detected bythe detection unit to determine a state change of a portion adjacent tothe RPE cell layer.

The control unit adjusts a magnitude of energy transferred per unit areaof a treatment area by the treatment beam based on state informationabout a treatment area detected by the monitoring unit. The control unitmay control the treatment beam generation unit to gradually increaseenergy transferred per unit area of a treatment area, if a change ofstate information about the treatment area detected by the monitoringunit is less than or equal to a reference value.

In accordance with another aspect of the present invention, a method ofdriving an ophthalmic treatment device includes: radiating a treatmentbeam to a target position by driving a treatment beam generation unit;radiating a detecting beam to a treatment area in which the treatmentbeam is radiated by driving a monitoring unit and detecting stateinformation about the treatment area based on interference informationof the detecting beam reflected from the treatment area; and adjusting,by a control unit, operation of the treatment beam generation unit basedon the detected state information.

Here, the detecting of state information about the treatment area mayinclude detecting state information about the treatment area bydetecting a speckle pattern of the detecting beam. The detecting ofstate information about the treatment area may include extractinginformation corresponding to an interest depth region among interferenceinformation by the detecting beam.

Specifically, the detecting of state information about the treatmentarea may include: detecting a speckle pattern from the detecting beam;extracting information about an interest depth region corresponding toan RPE cell layer from the speckle pattern; and determining a specklepattern change amount of the interest depth region to determine a statechange of the treatment area.

Advantageous Effects

According to the present invention, by performing a treatment bydetecting state information within a treatment area, an optimizedtreatment can be performed, and damage due to deterioration of aperiphery of the treatment area can be prevented.

Further, by detecting state information using a speckle pattern of adetecting beam, a treatment that reflects a micro state change can beperformed, and by extracting and analyzing only information about aspecific area among acquired information and by minimizing a time to beconsumed for analysis, monitoring similar to real time can be performed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram illustrating an ophthalmic treatmentdevice according to an exemplary embodiment of the present invention;

FIG. 2 is an enlarged cross-sectional view of an area A of FIG. 1;

FIG. 3 is a diagram illustrating a tomogram structure in which atreatment beam and a detecting beam are radiated;

FIG. 4 is a graph illustrating an example of a signal detected by adetection unit;

FIG. 5 is a flowchart illustrating a method of driving the ophthalmictreatment device of FIG. 1;

FIG. 6 is a flowchart illustrating step of detecting a state of atreatment area in FIG. 5;

FIG. 7A and FIG. 7B are graphs illustrating examples of a first modeoperation and a second mode operation in FIG. 5; and

FIGS. 8A to 8D are graphs illustrating examples of a first modeoperation of FIG. 5 according to another exemplary embodiments of thepresent invention.

BEST MODE

Hereinafter, an ophthalmic treatment device according to an exemplaryembodiment of the present invention will be described in detail withreference to the drawings. In the following description, a positionrelationship of each element will be described based on the drawing. Forconvenience of description, the drawing may simplify a structure of theinvention or may be exaggeratingly displayed, as needed. Therefore, thepresent invention is not limited thereto and various devices may beadded, changed, or omitted.

In the present exemplary embodiment, an example of an ophthalmictreatment device for treating a lesion of a fundus area such as a retinawill be described. However, the present invention is not limited theretoand may be applied to a treatment device that treats a lesion other thana fundus area. For example, the present invention may be applied to anophthalmic treatment device to be used for a treatment of an anteriorsegment of eye such as a patient's cornea and may be applied to adermatological treatment device for treating a lesion such as a skinpigment and a blood vessel in addition to an ophthalmic lesion.

FIG. 1 is a schematic diagram illustrating an ophthalmic treatmentdevice according to an exemplary embodiment of the present invention. Asshown in FIG. 1, an ophthalmic treatment device 10 according to anexemplary embodiment of the present invention includes a treatment beamgeneration unit 100 that generates a treatment beam, an aiming beamgeneration unit 200 that generates an aiming beam, and a beam deliveryunit 400 that forms a path in which a treatment beam and an aiming beamadvance to a treatment area. Further, the ophthalmic treatment device 10includes a monitoring unit 300 that detects state information about atreatment area and a control unit 500 that controls driving of thetreatment beam generation unit based on information detected in themonitoring unit.

The treatment beam generation unit 100 may include a treatment beamlight source that generates a treatment beam and various opticalelements that process a characteristic of light generated in thetreatment beam light source. The treatment beam is configured withlaser, and the treatment beam light source may include a laser medium ora laser diode such as Nd:YAG and Ho:YAG that may oscillate laser. Thetreatment beam generation unit 100 may include various electric circuitsfor exciting laser, an optical filter for oscillating light of aspecific wavelength among various wavelength bands, and various elementssuch as a shutter.

The ophthalmic treatment device 10 according to the present exemplaryembodiment treats various lesions occurring in a fundus area such asmacular degeneration, and a treatment beam selectively provides energyto a specific target position (e.g., RPE cell layer). Therefore, thetreatment beam may use laser having a pulse width to be selectivelyabsorbed to melanosome of an RPE cell among various cell layers forminga retina. Specifically, the treatment beam may use laser of a visibleray to near-infrared ray range.

The aiming beam generation unit 200 generates an aiming beam to beradiated to a treatment area. The aiming beam notifies a position inwhich a treatment beam is to be radiated to an operator before thetreatment beam is radiated or while the treatment beam is radiated. Theaiming beam has a wavelength of a visible light band, and the operatormay determine a treatment area by an aiming beam reflected from thetreatment area.

An aiming beam generated in the aiming beam generation unit 200 may beradiated to indicate one spot in which a treatment beam is radiated fromthe treatment area. Alternatively, an aiming beam may be radiated toindicate a pattern in which a treatment beam is continuously radiated orto simultaneously indicate a plurality of spots.

In addition, an aiming beam may be radiated to form an image of alattice form or a boundary line form instead of a spot form to displayan area in which a treatment beam is to be radiated. In this case, theaiming beam may be radiated along a path different from that of atreatment beam.

However, when an operator can determine a treatment area through aseparate interface such as a monitor, the aiming beam generation unitmay be omitted.

The beam delivery unit 400 is configured with a plurality of opticalelements disposed between the treatment beam generation unit 100 and acontact lens 600 that fixes a patient's eye. The beam delivery unitconfigures a light path along which a treatment beam radiates. Theaiming beam and a detecting beam of a monitoring unit to be describedlater advance along beam delivery unit. In this case, the aiming beamand the detecting beam may radiate along a path including at least aportion of a light path of the treatment beam. However, the aiming beamor the detecting beam may have a separate light path from that of thetreatment beam.

Specifically, as shown in FIG. 1, the beam delivery unit includes aplurality of beam combiners 420. Thereby, a treatment beam, an aimingbeam, and a detecting beam each may enter into the beam delivery unit tobe radiated to a treatment area. The aiming beam and the detecting beameach reflected from the treatment area may advance in a direction of alens 700 in which an operator's eye is positioned or may be againapplied to the monitoring unit 300 through the beam delivery unit 400.

The beam delivery unit 400 may include a scanner 410 for changing aposition at which a beam is radiated. The scanner 410 may include atleast one reflection mirror and a driver that rotates the at least onereflection mirror and change a radiation position of a beam while arotation position of a reflection mirror that reflects the beam changes.

In addition, the beam delivery unit 400 may further include an opticalelement (not shown) such as a plurality of optical lens and opticalfilters for focusing or dispersing light.

In an end portion of the beam delivery unit 400, the contact lens 600may be provided. The contact lens 600 is a portion that contacts apatient's eye and performs a function of fixing the patient's eye whileperforming an operation. The contact lens 600 includes a lens in which abeam advances and may include a suction device that fixes a patient'seye in some case.

FIG. 2 is an enlarged cross-sectional view of an area A of FIG. 1. FIG.2A is a diagram illustrating a patient's retina tissue corresponding toa treatment area. Such a retina tissue is generally formed with 10layers of an internal limiting layer, a nerve fiber layer, a ganglioncell layer, an inner plexiform layer, an inner nuclear layer, an outerplexiform layer, an outer nuclear layer, an external limiting layer, aphoto receptor layer, and a retinal pigment epithelial layer (RPElayer).

The RPE cell layer forms a boundary layer of a rear direction among the10 layers and is formed in a tight junction structure. At a lowerportion of the RPE layer, a Bruch's membrane is positioned. Such an RPElayer performs a function of supplying nutrients and oxygen from a bloodvessel positioned at a lower portion of the Bruch's membrane to a photoreceptor and discharging waste generated in the photo receptor throughthe Bruch's membrane.

Here, when some RPE cells forming the RPE layer do not perform a normalfunction, nutrients and oxygen are not regularly supplied to photoreceptors of a position corresponding to the RPE cell and thus the photoreceptors are necrotized. Therefore, the ophthalmic treatment deviceaccording to the present exemplary embodiment radiates a treatment beamto an RPE cell that does not perform a normal function to selectivelynecrotize the RPE cell, thereby inducting regeneration of a new RPEcell.

Specifically, a treatment beam generated in the treatment beamgeneration unit 100 has a predetermined wavelength corresponding to avisible ray or near-infrared ray range. Light of a correspondingwavelength is scarcely absorbed but transmitted to a cell layer (firstcell layer to ninth cell layer) positioned at the front side of a retinaand is absorbed to melanosome existing within an RPE cell of the RPEcell layer. Therefore, as an amount of energy absorbed to melanosomeincreases with radiation of a treatment beam, a temperature of themelanosome increases and thus thermal damage occurs in a correspondingRPE cell. As a temperature increases, a microbubble occurs at a surfaceof melanosome, and as the microbubble gradually grows, a correspondingRPE cell selectively necrotizes. At a position of an RPE cell in whichthermal damage has occurred, a new RPE cell is regenerated and thus atreatment is performed.

Here, when a treatment beam is excessively much radiated, thermal damagemay occur in adjacent RPE cells and photoreceptors as well as an RPEcell to which the treatment beam is radiated. Therefore, the ophthalmictreatment device of the present exemplary embodiment includes themonitoring unit 300, and the monitoring unit 300 detects stateinformation about a treatment area while a treatment is performed.

Referring again to FIG. 1, the monitoring unit 300 radiates a detectingbeam to the treatment portion and acquires scattering and specklepattern information about the treatment portion. The detecting beamarrived at the treatment area through such a beam delivery unit 400 isreflected by mediums of the treatment area to direct backward antraveled path and to be received in the monitoring unit 300.

Here, a detecting beam is configured with light of a wavelength having aproperty less absorbed to a tissue and having excellent transmittance.While a detecting beam radiated to a treatment area advances from asurface to the inside of a retina, the detecting beam passes through atissue or an interface having different refractive indexes to bescattered or reflected. Therefore, interference information of thereflected detecting beam may include speckle information about eachposition while advancing from a surface of the treatment area to an RPEcell layer.

Accordingly, the monitoring unit 300 analyzes an interferenceinformation change of the received detecting beam to detect state changeinformation about the treatment area. Here, state change informationabout the treatment area may include at least one of a temperaturechange, a volume change, and a refractive index change of a tissueoccurring in the treatment area while a treatment beam is radiated, andinformation on whether cells are moved.

When a treatment beam is radiated to the treatment area, a temperatureof a tissue increases and thus a volume of the tissue changes, a tissuecharacteristic changes, or a partial tissue moves and thus an advancingcharacteristic of light that passes through the tissue changes (e.g., alight path length, a speckle pattern). Therefore, while a treatment isperformed, a characteristic of a reflected detecting beam changes, andthe monitoring unit 300 may detect a state change of a treatment areabased on a characteristic change of a received detecting beam.

Specifically, the monitoring unit 300 according to the present exemplaryembodiment may be configured using an Optical Coherent Tomography (OCT)device. Such an OCT device obtains tomography information about a tissueusing interference information of light. A kind of Time Domain OCT (TDOCT), spectral domain OCT (SD OCT), and swept source OCT (SS OCT) mayexist according to a drive method and a measurement method, and in thepresent exemplary embodiment, the SD OCT or the SS OCT may be used.However, conventional OCT acquires tomography information while moving acoordinate in a horizontal direction (B-scan), however in the presentexemplary embodiment, tomography information about a tissue can beobtained at the same position through Z-scan without separate B-scanwhile monitoring a specific treatment position.

As shown in FIG. 1, the monitoring unit 300 includes a light source 310,a beam splitter 320, a reference beam reflector 330, a detection unit340, and a processor 350.

The light source 310 may be a light source that generates a low coherentbeam in SD OCT and may be a swept source light source that may change awavelength of light in SS OCT.

Light emitted from the light source 310 is divided into two beams of adetecting beam and a reference beam while passing through the beamsplitter 320. The reference beam travels to a reference beam reflectordirection along a first path P1 and is reflected from the reference beamreflector 330. The detecting beam travels along a second path P2,advances through the beam delivery unit 400 to the treatment area andthen is reflected. Portions of the reflected detecting beam and thereference beam are combined in the beam splitter 320 to be applied tothe detection unit 340.

Interference occurs in the combined detecting beam and reference beam,and the detection unit 340 may detect speckle state information about atreatment area using interference information of the received detectingbeam and reference beam. Here, the detection unit 340 may use an arraydetector in the SD OCT and use a photo diode in the SS OCT.

When the combined detecting beam and reference beam are applied, such adetection unit 340 may separate the combined detecting beam andreference beam on a wavelength band basis to acquire state informationaccording to a depth of a treatment area using a signal in which aFourier transform processing is performed. A signal detected by thedetection unit 340 may acquire various forms of information about atreatment area according to processing contents, and in the presentexemplary embodiment, speckle pattern information of the detecting beammay be acquired.

The speckle pattern means an intensity pattern occurring by mutualinterference between rays constituting light. Such a speckle pattern mayform different patterns according to a position of a light path, and asurface characteristic of a reflection surface and scatteringinformation occurring when light passes through a tissue is reflected toeach speckle pattern. When a micro change occurs on a light path, aninterference pattern changes between rays and thus a speckle pattern ofa corresponding position changes.

In this way, state information about a treatment area is reflected to aspeckle pattern of a detecting beam detected by the detection unit 340.Therefore, by detecting a change of a speckle pattern while performing atreatment, it is possible to determine a micro state change of atreatment area such as temperature increase, a change of a tissuethickness, a change of a refractive index, and a tissue movement.

Therefore, the processor 350 analyzes a change of a signal (e.g.,speckle pattern) detected by the detection unit 340 to determine a statechange of a treatment area. When a state change of the treatment area isdetected, in order to change treatment contents by reflecting the statechange, the processor 350 may provide state change information to thecontrol unit 500.

FIG. 3 is a diagram illustrating a tomogram structure of a fundus inwhich a treatment beam and a detecting beam are radiated. As describedabove, the monitoring unit 300 radiates a detecting beam to a treatmentarea S while a treatment is performed and detects a state informationchange of a treatment area using the reflected detecting beam (see FIG.3).

More specifically, while a treatment is performed, the light source 310radiates a detecting beam multiple times to the treatment area S. Thedetection unit 340 continuously detects a signal by the reflecteddetecting beam. A signal obtained from the detection unit by thedetecting beam includes state information about the treatment area at acorresponding time point. Therefore, the monitoring unit 300 accordingto the present exemplary embodiment may acquire in real time stateinformation about the treatment area while performing a treatment.

The processor 350 may detect whether a state of the treatment area ischanged with a method of comparing a signal detected by each detectingbeam. For example, the processor 350 may determine whether a state ischanged with a signal detected by the detection unit 340 by eachdetecting beam (e.g., n-th detecting beam) and a signal detected by apreviously radiated detecting beam (e.g., (n−1)th detecting beam) basedon a value analyzed with cross correlation. Alternatively, the processor350 may determine whether a state of a signal detected by each detectingbeam and a signal detected by a detecting beam (e.g., a first detectingbeam) to be a reference is changed based on a value analyzed with crosscorrelation. In the present exemplary embodiment, a signal to be atarget that calculates cross correlation is a speckle pattern signaldetected by the detection unit, but various forms of signals may beused.

FIG. 4 is a graph illustrating an example of a signal acquired in aprocessor. Here, a signal detected by a detection unit includesinformation about an entire depth of a fundus corresponding to anadvancing path of a detecting beam. Specifically, a signal acquired byone detecting beam may include entire state information about aphotoreceptor layer, an RPE cell layer, and a Bruch's membrane layerfrom a retina surface (see FIG. 3). Therefore, in the present exemplaryembodiment, in a signal detected by the detection unit, only informationabout a specific concern area (hereinafter, referred to as a ‘interestdepth region’) Dsel is selectively extracted and it may be detectedwhether a state is changed based on the extracted information about theinterest depth region.

Specifically, when a signal is detected by any one detecting beam, onlyinformation about a specific concern area Dsel is extracted. Theprocessor 350 may determine whether a state of information about aninterest depth region by a current detecting beam (e.g., nth detectingbeam) and information about an interest depth region by a previouslyradiated detecting beam (e.g., (n−1)th detecting beam) is changed bycross correlation (here, while the detecting beam is continuouslyradiated, in a state in which B-scan is not performed, the detectingbeam is radiated to the same position).

In this case, a calculation amount that should process remarkablyreduces and thus fast calculation can be performed, compared with acalculation processing using an entire detected signal. Therefore, byminimizing a time to be consumed in analyzing state information,monitoring similar to real time can be performed.

Further, when performing calculation that detects a change between aprevious signal and a current signal, if a comparison is performed byselecting only a signal of an interest depth region in which a statechange most actively represents, a change rate is remarkably largelyrepresented, compared with a case of comparing an entire signal.Therefore, it may be accurately determined whether a state of atreatment area is changed.

Here, the interest depth region Dsel may be a tissue to be a targetwhile performing a treatment, a tissue in which a state change earliestoccurs, or a depth region in which a tissue having a large state changeamount is positioned. In the ophthalmic treatment device 10 according tothe present exemplary embodiment, as described above, a most treatmentbeam is absorbed to an RPE cell layer and thus while a temperature ofthe RPE cell layer increases, a state thereof is changed and thus in thepresent exemplary embodiment, the interest depth region may be set to adepth including the RPE cell layer. For example, an area from 50% pointto 100% point of a thickness from a retina surface in an outsidedirection (low direction of FIG. 3) may be set to an interest depthregion, and more specifically, an area from 70% point to 100% point of aretina thickness from a retina surface may be set to an interest depthregion.

In the present exemplary embodiment, because a device that treats alesion of a fundus area is described, an RPE cell layer and an adjacentarea are set to an interest depth region, but various applications maybe performed. For example, when treating a cornea, a specific depthregion within a stroma may be set to an interest depth region, and aninterest depth region may be differently set according to a treatmentlesion.

Such an interest depth region Dsel may use a predetermined value, but inthe present exemplary embodiment, a user may set an interest depthregion Dsel through an interface (not shown) in consideration of atreatment lesion and a patient's characteristic. Because a state and athickness of a retina are different according to a patient, an interestdepth region may be set in consideration of a patient's retinatomography image photographed when performing checkup.

In this way, the processor 350 compares a signal of an extractedinterest depth region Dsel to determine a state change of a treatmentarea, and such a determination method may be configured with variousmethods.

For example, if a change amount of an extracted signal is equal to orless than a predetermined value (first predetermined value), comparedwith a previous signal, it may be determined that a state of thetreatment area is not changed, and if a change amount is larger than apredetermined value, it may be determined that a state of a treatmentarea is changed.

In another example, as described above, when a temperature of the RPEcell increases with radiation of a treatment beam, while a microbubbleoccurs, a volume of the RPE cell gradually expands. Therefore, in thisway, while a temperature of the RPE cell sequentially increases, adetection signal sequentially changes. At a time point (e.g., adestruction time point of the RPE cell) at which the RPE cell necrotizeswith a continuous treatment, the detection signal may discontinuouslychange. Therefore, if a change amount of an extracted signal is equal toor less than a predetermined value (second predetermined value), theprocessor 350 may determine to continuously increase a temperature in astate in which the RPE cell does not necrotize, and if a change amountof an extracted signal is larger than a predetermined value, theprocessor 350 may determine that the RPE cell is necrotized.

In another example, the processor 350 may compare a change amount of anextracted signal with previously stored reference data, determine atemperature of the treatment area, and estimate and determine a statechange of a treatment area based on the determined temperature. While atreatment beam is radiated, before a necrosis time point (thermal damageoccurrence time point) of the RPE cell, even if a temperaturecontinuously increases, a change amount of the detected signal isminute, but a signal change detected at a necrosis time point rapidlyoccurs. Therefore, before the RPE cell is necrotized, it is difficult toestimate a necrosis time point of the RPE cell or to adjust treatmentcontents in consideration of a temperature of the RPE cell. Therefore,the ophthalmic treatment device may have a signal value (or a changeamount of a signal) detected by a detecting beam and reference dataabout temperature information corresponding thereto. The processor maycompare a signal detected by a detecting beam with reference data whileperforming a treatment, determine temperature information of an interestdepth region in real time, and control treatment contents inconsideration of the temperature information.

In this way, by selectively extracting and processing signal informationcorresponding to a depth of an interest depth region Dsel, particularlya RPE cell, the monitoring unit 300 according to the present exemplaryembodiment may detect state information about the RPE cell whileperforming a treatment. Particularly, the monitoring unit 300 maymonitor a micro state change during a time period in which a temperatureincreases in a treatment process as well as information about a timepoint in which a treatment of the RPE cell is complete while performinga treatment. Therefore, according to the present exemplary embodiment,an adjacent tissue may be prevented from being thermally damaged due toexcessive radiation of a treatment beam, and by accurately transferringenergy of a desired amount, an optimal treatment can be performed.

The control unit 500 controls operation of various constituent elementssuch as the treatment beam generation unit 100, the aiming beamgeneration unit 200, and the beam delivery unit 400. In this case, stateinformation about a treatment area detected by the monitoring unit 300is transferred to the control unit 500, and the control unit 500 maycontrol various constituent elements based on state information about atreatment area.

The control unit 500 may control operation of the treatment beamgeneration unit 100 according to state information about a treatmentarea. For example, the control unit 500 may variously control treatmentbeam parameters such as an output of a treatment beam, a pulse time of atreatment beam, a time between pulses constituting a treatment beam, ora focus level of a treatment beam.

In this way, the monitoring unit monitors a treatment process and thecontrol unit adjusts treatment contents in consideration of themonitored treatment process and thus the ophthalmic treatment device 10according to the present exemplary embodiment may perform an optimaltreatment. The control of treatment contents in consideration of atreatment process may be designed with various methods, and hereinafter,as an example, a method of driving an ophthalmic treatment deviceaccording to the present exemplary embodiment will be described.

FIG. 5 is a flowchart illustrating a method of driving the ophthalmictreatment device of FIG. 1. When a treatment area is determinedaccording to a checkup result of a patient's lesion, the patient eyeballis fixed to the contact lens 600 (S10).

The control unit 500 drives the treatment beam generation unit 100 toradiate a treatment beam to the patient's fundus fixed to the contactlens 600 in a first mode M1 (S20). In the first mode, the treatment beamis radiated multiple times and is radiated in a pattern sequentiallyincreasing from energy of a low magnitude provided to a unit area of atreatment area per unit time. Thereby, the control unit 500 can preventan adjacent tissue from being damaged by transferring excessive energyto the treatment area.

While the foregoing step is performed, the monitoring unit 300 radiatesa detecting beam to a position in which a treatment beam is radiatedmultiple times and receives the reflected detecting beam to continuouslydetect a state of the treatment area (S30). In this case, each detectingbeam may be controlled to be radiated simultaneously with the treatmentbeam or a detecting beam and a treatment beam may be controlled to bealternately radiated.

FIG. 6 is a flowchart illustrating step of detecting a state of atreatment area in FIG. 5. Hereinafter, the step will be described inmore detail with reference to FIG. 6.

A light source of the monitoring unit 300 radiates a detecting beam to atreatment area in which a treatment beam is radiated (S31). The radiateddetecting beam advances to the inside of a retina corresponding to thetreatment area and is scattered or reflected.

The detection unit 340 detects a speckle pattern of a detecting beamfrom interference information of the scattered or reflected detectingbeam and a reference beam (S32). Here, the speckle pattern of thedetecting beam may include information according to each depth of aretina tomography through which the detecting beam is passed.

The detection unit 340 extracts a speckle pattern of an interest depthregion, i.e., a partial area including an RPE cell layer among thedetected speckle pattern (S33). The RPE cell layer is an area in which astate change most sensitively occurs by a treatment beam. Therefore, thedetection unit 340 or the processor 350 excludes information about anunnecessary depth region in the speckle pattern of the detecting beamand extracts speckle pattern information about a concern RPE cell layer.

The processor 350 determines a state of a treatment area, specifically astate of the RPE cell layer of a treatment area based on the extractedspeckle pattern change information about the RPE cell layer (S34). Inthis case, the processor 350 detects a state of a treatment area with amethod of detecting a change amount of speckle pattern information aboutthe RPE cell layer by this detecting beam (e.g., n-th detecting beam)and speckle pattern information about the RPE cell layer by a previousdetecting beam (e.g., (n−1)th detecting beam) by cross correlation.Alternatively, a state of a treatment area may be detected with a methodof detecting a change amount of speckle pattern information about an RPEcell layer by this detecting beam (e.g., n-th detecting beam) andspeckle pattern information about an RPE cell layer by an initialdetecting beam (e.g., first detecting beam) by cross correlation.

FIG. 6 illustrates step by one detecting beam of a plurality ofdetecting beams radiated in a monitoring process, but at this step,while a plurality of detecting beams are radiated, by repeatedlyperforming the steps S31 to S34 for an entire detecting beam, stateinformation about an RPE cell layer of a treatment area may becontinuously detected while performing a treatment.

Referring again to FIG. 6, when state information about the treatmentarea detected through the foregoing step is detected, the control unit500 determines whether a state information change is larger than apredetermined reference value (S40). At this step, it is determinedwhether a change amount of a speckle pattern performed at the foregoingstep is larger than a predetermined reference value. Here, a referencevalue may be variously designed according to treatment contents. Forexample, a reference value may be set in consideration of a changeamount when thermal damage occurs in a treatment area or may be set inconsideration of a corresponding change amount when a treatment areaarrives at a specific temperature.

Through this step, if state information about a treatment area is equalto or less than a reference value, the control unit 500 may control tomaintain a treatment in a current first mode M1. However, if stateinformation about a treatment area exceeds a reference value, thecontrol unit 500 may convert a mode of the treatment beam generationunit to a second mode M2 to control the treatment beam generation unitto operate in the second mode M2 (S50).

FIG. 7A and FIG. 7B are graphs illustrating examples of a first modeoperation and a second mode operation in FIG. 5. As described above, inthe first mode M1, the treatment beam generation unit 100 generates atreatment beam such that energy transferred to a unit area of atreatment area per unit time sequentially increases. However, in thesecond mode M2, it is determined that a temperature of a RPE cellincreases to a temperature adjacent to a predetermined temperature,energy transferred to an unit area of a treatment area per unit timeincreases no longer, and a treatment beam may be generated to maintain acurrent state (FIG. 7A). Alternatively, a treatment beam may begenerated to reduce an increase width of energy transferred to a unitarea, compared with the first mode (FIG. 7B).

In this way, even while a treatment beam is radiated in the second modeM2, the monitoring unit 300 monitors state information about a treatmentarea based on a continuously detected signal. The monitoring unit 300continuously determines whether a signal (e.g., a signal correspondingto necrosis of the RPE cell) is detected representing whether the RPEcell arrives at a predetermined temperature.

Through the above process, until a treatment completion signal isdetected, operation of the second mode M2 may be continued, and at atime point at which a treatment completion signal is detected, radiationof a treatment beam to a corresponding treatment area may be terminatedand a treatment may be performed in other treatment areas by changing atreatment beam radiation position to a next treatment area.

When performing the foregoing method of driving the ophthalmic treatmentdevice, in the control of the first mode M1 that sequentially increasesenergy transferred to a unit area of a treatment area per unit time, inshown in FIG. 7A and FIG. 7B, the first mode M1 was controlled with amethod of sequentially increasing an output of a pulse of a treatmentbeam. However, this is an example and the first mode may be implementedby controlling other variables other than an output of a treatment beam.

FIGS. 8A to 8D are graphs illustrating examples of a first modeoperation of FIG. 5 according to another exemplary embodiments of thepresent invention. For example, as shown in FIG. 8A, the treatment beamgeneration unit generates a pulse of the same output having the samepulse duration time, but by gradually reducing an off time between eachpulse, the treatment beam generation unit may sequentially increase amagnitude of energy transferred per unit area. Alternatively, as shownin FIG. 8B, the treatment beam generation unit generates a pulse of thesame output, but by gradually increasing a pulse duration time of eachpulse, the treatment beam generation unit may sequentially increase amagnitude of energy transferred per unit area. In addition, the firstmode and the second mode may be implemented with various methods such asa method of radiating one pulse of a treatment beam into a plurality ofunit pulses having the same output, but of sequentially increasing thenumber of a unit pulse constituting one pulse, as shown in FIG. 8C or amethod of sequentially increasing a magnitude of energy transferred perunit area of a treatment area with a method of gradually focusing atreatment beam, as shown in FIG. 8D.

Further, in the method of operating an ophthalmic treatment device, ithas been described that treatment contents are controlled in two modesaccording to state information about a treatment area, but forconvenience of description, a simple example is described, and variouslychanges and designs may be performed according to a patient's lesioncontents and treatment area.

Further, in the present exemplary embodiment, a signal detected in themonitoring unit was used for only monitoring a state of a treatmentarea, but a separate display may be provided, and by displaying atomography image of a treatment area in the display, a user may directlydetermine an RPE cell state of the treatment area while performing atreatment.

While this invention has been described in connection with what ispresently considered to be practical exemplary embodiments, it is to beunderstood that the invention is not limited to the disclosedembodiments, but, on the contrary, is intended to cover variousmodifications and equivalent arrangements included within the spirit andscope of the appended claims.

1. An ophthalmic treatment device, comprising: a treatment beamgeneration unit that generates a treatment beam; a beam delivery unitthat forms a path along which the treatment beam generated by thetreatment beam generation radiates to a treatment area positioned at afundus; a monitoring unit that radiates a detecting beam to thetreatment area and that detects state information of the treatment areabased on interference information of the detecting beam scattered orreflected from the treatment area; and a control unit that controlsoperation of the treatment beam generation unit based on the stateinformation of the treatment area detected in the monitoring unit. 2.The ophthalmic treatment device of claim 1, wherein the monitoring unitdetects speckle pattern information of the detecting beam scattered orreflected from the treatment area to detect state information of thetreatment area.
 3. The ophthalmic treatment device of claim 1, wherein,while the treatment beam is radiated to one treatment position, themonitoring unit radiates the detecting beam multiple times to thetreatment position to detect state information of the treatmentposition.
 4. The ophthalmic treatment device of claim 3, wherein themonitoring unit compares state information detected by each detectingbeam with state information detected by the previously radiateddetecting beam to determine a state change of the treatment area.
 5. Theophthalmic treatment device of claim 4, wherein the monitoring unitselectively extracts information corresponding to an interest depthregion among state information detected by the each detecting beam andcompares the extracted information about the interest depth region withinformation about the interest depth region detected by a previouslyradiated detecting beam to determine whether a state of the treatmentarea is changed.
 6. The ophthalmic treatment device of claim 5, whereinthe interest depth region encompass a depth region in which an RPE celllayer is positioned within the treatment area.
 7. The ophthalmictreatment device of claim 5, wherein a depth corresponding to theinterest depth region is directly set by a user through an interface. 8.The ophthalmic treatment device of claim 1, wherein the monitoring unitdetects a temperature change of the treatment area occurring during thetreatment beam is absorbed in the treatment area.
 9. The ophthalmictreatment device of claim 1, wherein a characteristic of a light pathalong which the detecting beam radiates is changed as a refractive indexor a volume of a tissue positioned at the treatment area changes withtemperature increase of the treatment area, and wherein the monitoringunit detects a temperature change of the treatment area by detecting aspeckle pattern change of the detecting beam caused by the change of thecharacteristic of the light path.
 10. The ophthalmic treatment device ofclaim 9, wherein the monitoring unit determines that a temperature ofthe RPE cell continuously increases, if change amount of the specklepattern of the reflected detecting beam is in a predetermined range, anddetermines that the RPE cell is necrotized, if a change amount of thespeckle pattern of the reflected detecting beam exceeds thepredetermined range.
 11. The ophthalmic treatment device of claim 1,wherein the monitoring unit comprises: a light source that radiates thedetecting beam to the treatment area; a detection unit that detects aspeckle pattern of the detecting beam reflected from the treatment area;and a processor that extracts information about a portion adjacent to anRPE cell layer in the speckle pattern detected by the detection unit todetermine a state change of a portion adjacent to the RPE cell.
 12. Theophthalmic treatment device of claim 1, wherein the control unit adjustsa magnitude of energy transferred per unit area of the treatment area bythe treatment beam based on state information about the treatment areadetected by the monitoring unit.
 13. The ophthalmic treatment device ofclaim 12, wherein the control unit controls the treatment beamgeneration unit to gradually increase energy transferred per unit areaof the treatment area, if a change amount of state information about thetreatment area detected by the monitoring unit is less than or equal toa reference value.
 14. The ophthalmic treatment device of claim 13,wherein the control unit sequentially increases an output of a pulse ofthe treatment beam radiated by the treatment beam generation unit toincrease energy transferred per unit area of the treatment area.
 15. Theophthalmic treatment device of claim 13, wherein the control unitincreases a pulse duration time of the treatment beam radiated by thetreatment beam generation unit or sequentially reduces an off timebetween pulses of the treatment beam to increase energy transferred perunit area of the treatment area.
 16. The ophthalmic treatment device ofclaim 13, wherein the treatment beam generated in the treatment beamgeneration unit is configured with a pulse waveform, and each pulse isformed with a plurality of unit pulses, and wherein the control unitsequentially increases the number of a unit pulse constituting the pulseto increase energy transferred per unit area of the treatment area. 17.A method of driving an ophthalmic treatment device, the methodcomprising: radiating a treatment beam to a target position by driving atreatment beam generation unit; radiating a detecting beam to atreatment area, in which the treatment beam is radiated, by driving amonitoring unit and detecting state information about the treatment areabased on interference information of the detecting beam reflected fromthe treatment area; and adjusting, by a control unit, operation of thetreatment beam generation unit based on the detected state information.18. The method of claim 17, wherein in detecting of state informationabout the treatment area the state information about the treatment areais detected by detecting a speckle pattern of the detecting beam. 19.The method of claim 17, wherein the detecting of state information aboutthe treatment area comprises extracting information corresponding to aninterest depth region among interference information by the detectingbeam.
 20. The method of claim 17, wherein the detecting of stateinformation about the treatment area comprises: detecting a specklepattern from the detecting beam; extracting information about aninterest depth region corresponding to an RPE cell layer from thespeckle pattern; and determining a speckle pattern change amount of theinformation about the interest depth region to determine a state changeof the treatment area.